A liquid crystal display device has characteristics of low profile, low power consumption, digitization and the like, and is applied more and more widely in the market. Since the liquid crystals themselves do not emit light and cannot collect light from natural light, a stable and clear display must be obtained by using a backlight source. Generally, the electrical power of the backlight source is from an external cell such as a lithium cell, and it is not convenient for a user to charge the cell after its limited electrical storage is exhausted.
A solar cell is a device of using photovoltaic effect to convert solar energy into electrical energy. As shown in FIG. 1, in a conventional solar cell, when the N-type and P-type semiconductor materials contact, conductive particles diffuse and drift to form a built-in electric field with a direction from the N-type semiconductor material to the P-type semiconductor material at the interface of the two semiconductor materials. When light is incident onto the surface of the solar cell, photons provide energy to stimulate new electron-hole pairs in the semiconductor material. These stimulated electrons and holes apart from each other under the built-in electric field, and are rapidly accumulated at upper and lower electrodes of the solar cell, respectively. Based on this, the solar cell can supply power to a load connected to the two electrodes of the solar cell.
Since the solar power generation has advantages such as environmental protection, safety and the like, in a power consumption device such as a liquid crystal display device, the solar cell is used as efficiently as possible to collect light for producing energy, which will significantly facilitate saving of power consumption and environmental protection.
A conventional liquid crystal display device includes a driving circuit, an array substrate, a color filter substrate, a liquid crystal layer interposed between the array substrate and the color filter substrate, and a backlight source. When the liquid crystal display device operates normally, light emitted from the backlight source passes through the array substrate and irradiates onto the liquid crystal layer; and the driving circuit controls liquid crystal molecules in the liquid crystal layer to rotate by adjusting the distribution of the electric field between the array substrate and the color filter substrate, so that part or all of the light emitted from the backlight source transmits the liquid crystal layer and outgoes from the color filter substrate so as to achieve the display.
In a Chinese patent application with a publication number No. CN101813849A, a display device including solar cells is disclosed, and in the display device, the solar cells are located at the black matrixes of the color filter substrate, which is equivalent to replacing the black matrixes with the solar cells, to absorb the light emitted from the backlight source to convert light energy into electric energy for supplying power to the liquid crystal display device; in a Chinese patent application with a publication number No. CN101995691A, a display including solar cells is disclosed, and the solar cells are located at a non-light-transmissive part of the display to also absorb light emitted from the backlight source to convert light energy into electric energy for supplying power to the liquid crystal display device. These two patents only analyze the solar cells at the non-light-transmissive parts in the liquid crystal display device, and do not discuss the solar cells at light-transmissive part.